Search and rescue crews use side scan sonar to locate missing people - Search and Rescue Conference

A newer technology is being used by search and rescue crews to find people who have disappeared underwater.

After two days of extensive searching, dive teams used sonar to find Putnam County Deputy Brandee Smith’s body in the St. Johns River as reported by CBS.

The waters of the St. Johns River are murky, and just using the naked eye, search crews may never find a body. However, newer technology is giving them a leg up. Experienced diver Marshal Adkison said that regular sonar only allows you to see straight down, so you’re basically looking at the bottom of the river, but side scan sonar allows you to search a greater range.

Side-scan uses a sonar device that emits conical or fan-shaped pulses down toward the seafloor across a wide angle perpendicular to the path of the sensor through the water, which may be towed from a surface vessel or submarine, or mounted on the ship’s hull.

“They bring it back up, flip it around and bring the sides in so you can look out visually left and right,” said Adkison.
Adkison told Action News Jax his side scan sonar device isn’t as advanced as the one law enforcement uses. He showed us what search crews might see on their monitors when large objects are detected in the water.

“That’s one of the problems you run into is that old crab traps have ropes and they break so you have to go down and identify everything because that could be a body,” said Adkison.

Adkison said once they locate an object, search crews will send a diver to physically check it out. Some devices even record the sonar images, so crews can review the material. To watch the segment on CBS click here.